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U.S. Department of Energy
Office of Scientific and Technical Information

Individual cylinder ignition control

Patent ·
OSTI ID:6813039

An ignition system is described for providing individual cylinder spark control for multicylinder engines including a shaft encoder directly connected to the engine crankshaft, the encoder producing a large number of encoder pulses per engine revolution (NC), means connected to the shaft encoder producing a single timing reference pulse every other shaft revolution at the same reference shaft position. A first counter is connected to receive the timing reference pulses and the encoder pulses (NC) and to produce a carry pulse after every N counts where N is equal to 2NC/number of cylinders of the engine and N counts thus represents the theoretical crank angle between successive cylinder reference shaft positions, second and third counters connected to receive each carry pulse, the second counter delaying the carry pulse by a fixed number of encoder output pulses to produce a maximum timing advance. The third counter is incremented one step for each carry pulse and is also connected to be reset by each timing reference pulse to synchronize the third counter with engine rotation, memory means having memory locations containing code information representing actual measured individual offset crankshaft angles for each individual cylinder of the engine being controlled, a variable delay counter and means connecting the second counter to the memory means and to the variable delay counter to cause the memory means to unload a code number to the variable delay counter corresponding to the cylinder indicated by the third counter.

Assignee:
Allied Corp., Morristown, NJ
Patent Number(s):
US 4638780
OSTI ID:
6813039
Country of Publication:
United States
Language:
English